I made this tonight and added sliced red peppers and sliced mushrooms to bulk it up a bit. This made the sauce a little more watery, so I think I might try making the sauce on the side in a separate pan, but the red peppers added a nice sweetness and good color.

this is as good as any Alfredo sauce I've had. I made mine with shrimp instead of chicken and ate it over spinach. I also saved the remaining sauce for a low carb salad dressing. The rosemary makes it!